# A013181 (b-file synthesized from sequence entry) 0 0 1 1 2 -2 3 7 4 -28 5 193 6 -1400 7 13319 8 -139424 9 1721281 10 -23379712 11 357281351 12 -5951323904 13 108706678273 14 -2142923081728 15 45591739883975 16 -1037606714249216 17 25211971076762753 18 -650452080060399616